Fluid impulse torque tool



Jan. 7, 1964 D. K. SKOOG 3,116,617

FLUID IMPULSE TORQUE TOOL I I Filed Dec. 12', 1961 1 7 Sheets-Sheet 1 H,i (-A 7 1 I I f t I .I"33B B 33c F/G.

3% 25 N 5 INVENTOR DONALD K. 5/(006 HIS ATTORNEY Jan. 7, 1964 D. K.SKOOG 3,116,617

FLUID IMPULSE TORQUE TOOL Filed Dec. 12, 1961 v Sheets-Sheet 2 f TOTHROTTLE SWITCH INVENTOR F/G. 6. BY%

HIS A ORNEY Jan. 7, 1964 D. K. SKOOG FLUID IMPULSE TORQUE TOOL 7Shets-Sheet 3 Filed Dec. 12, 1961 INVENTOR DONALD K. 5/(006 4 A 6 K 4 rK I H "1% I 5 J m 4 /M7/ 4% /f wl/// 1 a 1 m a a 7.1%.; m x a M m HISORN D. K. SKOOG Jan. 7, 1964 D IMPULSE TORQUE TOOL 7 Sheets-Sheet 4Filed Dec. 12, 1961 INVENTOR DONALD K. 5/(006 m'w I. h 1 4 HIS A TOR N YJan. 7, 1964 Filed Dec. 12, 1961 D. K- SKOQG FLUID IMPULSE TORQUE TOOL'7 Sheets-Sheet 5 illllllll D FIG /4 INVENTOR DONALD K. 8/(006 4b I I "oa I V HIS A ORNEY Jan. 7, 1964 D. K. SKOOG 3,115,617

FLUID IMPULSE TORQUE TOOL Filed Dec. 12, 1961 7 Sheets-Sheet 6 T0 HYDRACYLINDER INVENTOR DONALD K. 5/(006 W HIS A ORNE Jan. 7, 1964 SKQQG3,116,617

FLUID IMPULSE TORQUE TOOL Filed Dec. 12, 1961 7 Sheets-Sheet 7 T0HYDRAULIC CYLINER INVENTOR DONALD K. .9/(006 HIS A TORNEY United StatesPatent 3,116,617 FLUID IMPULSE TORQUE TOOL Donald K. Skoog, Stamford,Conn., assignor to Ingersoll- Rand Company, New York, N.Y., acorporation of New Jersey Filed Dec. 12, 1961, Ser. No. 158,838 24Claims. (Cl. 64-26) The present invention relates to power tools and,more particularly, to an improved torque tool of the impulse type. Thisapplication is a continuation-in-part of US. patent application, SerialNo. 115,714, filed June 8, 196-1, by D. K. Slcoog and entitled PowerTool.

Heretofore, conventional portable, power operated tools for drivingnuts, bolts and screws or for applying a torque to other objects havebeen of the stall, clutch and impact type. While the stall type andclutch type tools give satisfactory torque control in most applications,these types are larger and hence heavier than the impact type tool.Further the stall type and clutch type tools are slower in operationthan the impact type tool. In addition the stall type and clutch typetools provide an undesirable torque reaction to the operator, whichtorque reaction is not present in a tool of the impact type.

In the impact type of tool the kinetic energy of the rotary hammer (oflarge mass) is transferred to the spindle (of relatively lower mass) bya collision between the jaws of the hammer and the spindle. Theseconventional impact tools have several limitations. First the rigid jawsof the hammer and the similar jaws of the spindle are relatively lightin order to satisfy the demand of the fabricating industries for a lightportable tool. However the forces between the jaws of the hammer and thejaws of the spindle are very high during the time of impacttherebetween, with resultant breakage or failure of such jaws and ashorter service life than in other conventional power tools, such asthose of the stall or clutch types. Secondly, with these conventionalimpact tool-s it is very diflicult to control or limit the final torqueon a threaded fastener to a final predetermined value withinsatisfactory limits of accuracy. Further the impact tools are difficultto manufacture because of their complicated structure and are rathernoisy in their operation.

it is the general object of the present invention to avoid and overcomethe foregoing and other difficulties of and objections to prior artpractices by the provision of an improved tool of the impulse type whichtool has all of the advantages of the stall type, clutch type and impacttype tools and none of the disadvantages thereof.

A further object of the present invention is the provision of an impulsetype tool which operates in a fluid at low force levels with resultantminimum wear and attendant longer service life than conventional impacttools.

Another object of the present invention is the provision of an impulsetool which is operable to control the final torque on a threadedfastener accurately and precisely within predetermined limits.

Still another object of the present invention is the provision of animpulse tool which, because of the simplicity of its structure, is easyto manufacture.

Yet another object of the present invention is the provision of animpulse tool which provides relatively quiet operation as compared to animpact tool.

A further object of the present invention is the provision of animproved tool of the impulse type, the major elements of which tool actto seal dynamically or :at high velocity and function as a valvestatically or at low velocity.

A still further object of the present invention is the provision of animpulse tool which is lighter in weight and faster in operation than thetools of the stall type and clutch type.

Another object of the present invention is the provision of a tooloperable as a source of impulses, which impulses can be utilized todrive a conventional reciprocating tool, such as a hammer, or aconventional rotary tool, such as a drill.

A further object of the present invention is the provision of an impulsetool which is operable to apply a torque or a series of impulses at anangle with respect to the longitudinal axis of the impulse tool.

The aforesaid objects of the present invention and other objects whichwill become apparent as the description proceeds are achieved byproviding an impulse tool for applying a predetermined torque to anobject. This impulse tool comprises housing means adapted to contain afluid, a spindle means rotatable in the housing means and in the fluidand adapted to engage the object, and drive means connected to thehousing means for rotating the housing means with respect to the objectand the spindle means. The spindle means is operable during a portion ofeach revolution of the housing means to dynamically seal off a portionof said fluid so that the pressure in the portion of the fluid and onthe spindle means increases, thus causing the spindle means to rotatewith respect to the housing means and to apply a torque to the object.Alternatively the spindle means is connected to the drive means and thehousing means is adapted to engage the object. In addition, the spindlemeans is aflixed to a stationary casing means and the impulses generatedwithin the housing means are transmitted by means of passage means inthe spindle means and through a flexible but rigid coupling means to aconventional tool. Alternatively the housing means is secured to thestationary casing means and the impulses are transmitted through passagemeans in, the housing means.

For a better understanding of the present invention reference should behad to the accompanying drawings, wherein like numerals of referenceindicate similar pants throughout the several views and wherein:

FIG. 1 is a side elevational view of the improved tool of the impulsetype, shown in engagement with a threaded fastener and with a stationarycasing means shown in vertical section;

FIG. 2 is a horizontal sectional view on a slightly reduced scale alongthe line lI-II of FIG. 1 in the direction of the arrows with thestationary casing means and a cylinder casing removed for clarity andshowing a spindle means of the improved tool at the midpoint of thedynamic sealing portion of its rotary path of movement;

FIG. 3 is a vertical sectional view along the line Ill- Hl of FIG. 2 inthe direction of the arrows with the reservoir means and valve meansomitted for clarity;

FIG. 4 is a fragmentary plan view illustrating the locking means forsecuring a rear end cap to a casing nut;

FIG. 5 is a fragmentary vertical sectional view along the line VV ofFIG. 2 in the direction of the arrows of the relief valve means and anassocited cut-out means;

PEG. 6 is 'a fragmentary horizontal sectional along the line VIVI ofPEG. 5 in the direction of the arrows illustrating the keying of arelief valve spring plate in a cylinder bushing;

FlG. 7 is an enlarged fragmentary vertical sectional view along the lineVII-VII of FIG. 2 in the direction of the arrows of one of the reservoirmeans;

FIGS. 8l-2 are diagrammatic plan views similar to (but on a smallersealer than) FIG. 2 illustrating the operation of the impulse tool;

FIG. 13 is a view similar to FIG. 1 showing the drive means connected tothe spindle means and the housing means adapted to engage a threadedfastener;

FIG. 14 is a fragmentary side elevational view partially in verticalsection showing an alternative embodiment of the drive means;

FIGS. 15, 15a and 15b are fragmentary side elevational views partiallyin section illustrating the use of the impulse type tool as a source ofimpulses for operating a conventional tool, such as a hammer;

FIGS. 16 and 16a are views similar to FIG. 12 showing the flow of thefluid from the high pressure portion of the cavity through passage meansin the spindle means and through passage means in the housing meansrespectively;

FIG. 17 is a fragmentary side elevational view of an alternativeembodiment of the tool shown in FIG. 15.

While the impulse tool of the present invention may be advantageouslyemployed for applying a torque to objects and as a source of fluidimpulses in general, the impulse tool of the present invention isparticularly adapted for use in coniunction with applying a torque to athreaded fastener and as a source of fluid impulses for driving aconventional tool and hence it has been so illustrated and will be sodescribed.

With specific reference to the form of the present invention illustratedin the drawings, and referring partic ularly to FIG. 1, the impulse toolof the present invention is indicated generally by the reference letterT.

As shown in FIG. 1 this impulse tool T has a housing means A adapted tocontain a fluid, such as oil F.

Housing Means In order to contain the oil F, the housing means A has acylindrical bushing 1 (FIGS. 2 and 3) provided with an eccentricallydisposed cavity 2 in which the oil F is disposed. The means utilized toretain the oil F within the cavity 2 comprises a front end cap 3 (FiG.3) and rear end cap 4 compressed against the bushing 1 by means of aflanged cylinder casing 5 (the flanged end of which engages the frontend cap 3) and an annular casing nut 6 in threadable engagement with theunflanged end of the cylinder casing 5. For the purpose of sealinglycontaining the oil F in the housing means A by sealing the abuttingsurfaces of the bushing 1 and the rear end cap 4 and the bushing 1 andthe front end cap 3, a rear cylinder seal, such as the O-ring 7, and afront cylinder seal, such as the O-ring 8, respectively, are utilized.

In order to lock the casing nut 6 in the desired position, the casingnut 6 is provided with a plurality of slots 9 (FIG. 4) on its innerperiphery and when one of such slots 9 is aligned with a threaded hole14 (FIG. 3) in the rear end cap 4, a screw 11 is inserted into theregistering slot 9 and hole and threaded into the latter. As shown inFIG. 3, a locking pin 5a prevents relative rotary movement between thecylinder casing 5 and front end cap 3. In addition, alignment pins 1aprevent relative rotary movement between the cylinder bushing 1 andfront end cap 3 and between the cylinder bushing 1 and rear end cap 4.

The means utilized to fill the cavity 2 with the oil F comprises afiller plug 12 threaded into a drainage hole 13 in the front end cap 3and sealed to the front end cap 3 by means of a filler plug seal, suchas an O-ring 14.

Within the housing means A, a spindle means B (FIGS. 1, 2 and 3) isrotatable in the housing means A and in the oil F and is adapted toengage (FIG. 1) an object, such as a nut N on a bolt S, to apply apredetermined torque thereto.

Spindle Means This spindle means B has a spindle 15 (FIG. 3) which has afront shaft portion 16 journaled in the front end cap 3 and a rear shaftportion 17 journaled in the rear end cap 4. The axes of the front shaftportion 15 and rear shaft portion 17 coincide with the axis of rotationof the housing means A.

To provide a rotary seal between the front shaft portion 16 and thefront end cap 3, a rear spindle seal ring 18 (which rotates with frontshaft portion 16) is disposed in a sealing cavity 19 in the front endcap 3 and is sealed by a rear spindle seal, suitably an O-ring 2t), andsecured to the front shaft portion 16. A front spindle seal ring 21 ,1

(which rotates with the front end cap 3) is sealed by a front spindleseal, suitably an O-ring 22, and secured to the front end cap 3. Therings 18 and 2 1 are compressed together by a spring washer 23 and aspindle seal retainer 24 in threadable engagement with the front end cap3 to provide a mechanical face seal between the rings 13 and 21.

So that the spindle means B may engage the nut N (FIG. 1), the frontshaft portion 16 having a squared drive 1611 carries a socket 25,contoured to receive the nut N. As shown in FIGS. 2 and 3, sealingmeans, such as a spindle blade 26, is reciprocable in a slot 27 in thespindle 15 and is biased by means of springs 27!! (FIG. 3) against theside wall of the cavity 2. The springs 27a are contained in holes 23 inthe spindlc 15 and in the spindle blade 26.

As shown in FIG. 2, the spindle 15 is provided with reverse valve meansfor permitting the flow of the oil F into and out of the slot 27 orspace behind the spindle blade 26.

This reverse valve means comprises a reverse ball passage 29 (FIGS. 2and 3) adapted to contain a reverse ball 39 by means of a shoulder 31and a reverse ball retainer 32, the reverse ball passage 2) being incommunication with the slot 27 (i.e. the space behind the spindle blade26, FIG. 3).

To provide means for rotating the housing means A with respect to thenut N and the spindle means B, the impulse tool T (FIG. 1) is providedwith drive means (FIG. 1).

Drive Means This drive means is suitably any source of rotary power,such as an air motor D, having its output shaft 33 connected to the rearend cap 4- of the housing means A and is utilized for rotating thelatter in either direction, as for example the clockwise directionindicated in FIGS. 1 and 2 by the arrows.

As shown in FIG. 1, the housing means A and the air motor D arecontained within a stationary casing means H, suitably comprising twoflanged members Hf and Hr, which flanged members (a front flanged memberHf and a rear flanged member Hr) are secured together by a plurality ofspaced bolts 33a and nuts 33b. The front shaft portion 16 of the spindlemeans B projects through a clearance aperture 33c in the front flangedmember H The means utilized to centralize the air motor D in the rearflanged member Hr comprises a removable insert 33d secured to the rearflanged member Hr by screws 33:2. The front flanged member Hf carries abushing 33 which centralizes the front shaft portion 16 (FIG. 1), of thespindle means B and permits the substantially frictionless rotation ofsuch spindle means B therein.

Before proceeding with a description of the operation of the impulsetool T (FIG. 1), it is deemed necessary to describe a relief valve means(FIGS. 5 and 6) for relieving the pressure in the cavity 2 (ashereinafter explained) when such pressure reaches a predetermined valuewhich corresponds to a desired torque on the nut N.

Pressure Relief Means While the pressure relief means may have manyforms, one suitable form identified generally by the reference letter Cis shown in FIGS. 5 and 6. This pressure relief means C is provided witha relief valve cavity 34 in the bushing 1, which cavity 34 has a reliefvalve seat 35 adjacent a relief valve inlet passage 36 (FIGS. 2 and 5)on which a relief valve ball 37 is normally seated.

The relief valve inlet passage 36 is in communication with the highpressure side of the cavity 2. Disposed below the relief valve ball 37is a relief valve ball cap 3h biased by a relief valve spring 39 and aspring compression control means to the position shown in FIG. 5 againstthe relief valve ball 37.

This spring compression control means has a relief valve spring plate4%} which engages the relief valve spring 39 5 and is keyed in a slot 41(FIG. 6) in the bushing 1 for reciprocable movement by means of a reliefvalve positioning screw 42 which is rotatably retained in the front endcap 3 and sealed thereto by means of a relief valve seal, suitably anO-ring 43.

By turning the relief valve position screw '42 to raise the relief valvespring plate til, the pressure (and hence the corresponding maximumtorque on the nut N) at which the pressure relief means C will open isincreased. The adjusted relief valve positioning screw 42 is thensecured in the adjusted position by a lock nut 42a.

As shown in FIGS. 2 and 5, a relief valve outlet passage 4d connects thecavity 34 with the low pressure side of the cavity 2.

In order to supply additional oil F to the cavity 2 in the event ofleakage of oil F therefrom and to limit the static pressure in thecavity 2 (if thermal expansion or contraction occurs) a pair ofreservoir means R (FIG. 2)

.are employed.

Reservoir Means Each reservoir means R is provided with a reservoircavity 45 in the bushing 1, in which cavity 45 a reservoir piston 46 isbiased by a spring 4 7 into engagement with the oil F and is sealedagainst the sidewalls of the cavity 45 by means of a reservoir seal,such as an O-ring 48.

To prevent the reservoir means R from interfering with the variable andrapidly changing pressure conditions within the cavity 2 duringoperation of the impulse tool T, a reservoir orifice 4? (which connectsthe cavities 45 and 2) is suitably of small and flow limiting diameter.In order to fill the reservoir cavity '45 with fluid F when the tool Tis assembled, a long screw (not shown) is inserted through hole 3a andis threaded into a threaded hole 46a. The long screw (not shown) and thereservoir piston are pulled downwardly, as viewed in FIG. 7, thuspermitting fluid F to flow through reservoir orifice 49 and into thereservoir cavity 45 to fill the latter.

So that the housing means A will not appreciably decelerate as suchhousing means A approaches the position shown in FIG. 2 and 11 and willquickly accelerate as it leaves the position shown in FIG. 2, thebushing 1 is suit-ably undercut at St and 51. Referring to FIG. 3wherein a pin ality f the spaced undercuts Sil are provided in thebushing :1, it will be appreciated that the undercuts 51 are similarlydisposed.

Operation Assume (for purposes of illustration) that the spindle means Band housing means A are in the positions shown in REG. 2 and spindlemeans B is in engagement with the nut N when the air motor D is actuatedby closure of a throttle or trigger switch (not shown) by the operator(not shown). At the start ofoperation of the oil F in cavity 2 isdivided by the spindle blade 26 and a first sealing portion on thehousing means A (between undercuts 5d, 5 1-) and a second sealingportion, such as a shank portion 52 of the spindle 15, into, a highpressure portion HP and a low pressure portion LP.

As the housing means A (having a relatively larger mass as compared withthe spindle means B) rotates (about 30) in clockwise direction (withrespect to the spindle means B) from the position shown in FIG. 2 to theposition shown in FIG. '8, the shank portion 52 encounters the undercut51 and oil F flows rapidly around such shank portion 52 with attendantrapid acceleration of the housing means A. When the housing means A hasreached the position shown in FIG. 9 (about 180 later) oil F is passingfreely between the spindle 15 and the cylinder bushing 1 due to theireccentric relationship. While the housing means A is moving through theposition shown in FIG. 10 and approaching the position shown in FIG. 11,the undercut 5d prevents deceleration of such housing means A. Afteralmost one revolution of the housing means A (about 351) and as shown inFIG. 11, clearance between the shank portion 52 and the cylinder bushingl is reduced to a minimum and the pressure in the now formed (anddynamicall sealed) portion HP in the cavity 2 rises very rapidly. Whilethe housing means A tends to decelerate, the increased pressure on thespindle blade 26 and the spindle 15 rotates the spindle means B inclockwise direction (as shown in FIG. 12) with attendant tightening ofthe nut N.

As there is a definite static leakage between the shank portion 52. ofthe spindle '15 and the bushing 1, around the spindle blade 26 andbetween the front end cap 3 and rear end cap 4, the torque of the airmotor D causes the housing means A to rotate past the sealed positions(FIGS. 2, 11 and 12) and to start the acceleration phase of the nextrevolution or cycle of operation of the impulse tool T. Thereafter theimpulse tool T operates through a series of successive impulses untilthe final predetermined torque of the nut N is attained thereonprecisely and accurately.

Since the torque applied by the spindle means B to the nut N isproportional to the pressure in the portion H? of the cavity 2 duringthe dynamic sealing phase of the cycle of operation of the impulse toolT, the pressure relief means C is adjusted so that when maximum pressure in portion HP (and hence maximum desired torque on the nut N) isproduced, the relief valve ball 37 (FIG. 5) is unseated and oil F flowsfreely from the portion HP through the inlet passage 35, the cavity 34and the outlet passage into the portion LP, thus tending to limit thepressure in the portion HP and preventing the application of greatertorque to the nut N.

In order to provide cut out means for the impulse tool T, "which cut outmeans is operable by the flow of oil F through the cavity 34 at maximumdesired torque, the cut out means Co such as, by way of example, thetype (illustrated in FIGS. 2 and 5) is utilized.

Cut Out Means When the maximum pressure is achieved within the highpressure portion HP of the cavity 2 (with resultant maxi-mum desiredtorque on the nut N) the oil P fiows (in the direction of the arrows inFIG. 5) around the relief valve ball 37 and relief valve ball cap 38 andthrough the relief valve passage 44 into a cavity 53 of the cut outmeans in the cylinder bushing i. In order to cause the pressure in thecavity 53, a restrictive orifice 44a is provided in the left handportion (FIG. 5) of tr e relief valve passage 44-. This oil P moves apiston 54 (retained in the cavity 53 by a piston retainer 55 and sealedtherein by a seal, such as an Q-ring 56) against the action of a spring56a from the solid line position (FIG. 5) to the dotted line positionshown in such figure. As a result, the now further extended piston 54will (during the next revolution of the housing means A) engages amovable contact 57 of a normally closed switch 5'8 mount- -ed on thefront flanged member Hf of the stationary casing means H and causeopening of the switch 58. This now opened switch 58 disposed in serieswith a throttle switch (not shown) of the impulse tool T then causes theair motor D to be shut off. It will be noted in FIG. 5 that the movablecontact 57 of the switch 58 is partially broken away to clearly show thedotted line extended position of the piston 5 Alternative Embodiments Itwill be understood by those skilled in the art that alternatively (asshown in FIG. 13) the drive means or air motor D may be connected to thespindle means B by securing the output shaft 33 of the air motor D tothe rear shaft portion 17 at 58a. A seal, such as an O-ring 58.5 or themechanical face seal shown in the lower portion of FIG. 3, seals therear shaft portion 17 to the rear end cap 4a. The housing means Acarries the socket 25 for engaging the nut N, so that the impulse isapplied to the housing means A (during the dynamic sealing portion ofthe operating cycle of the impulse tool T) to cause the housing means Ato apply the torque to the nut N. During a portion of each revolution ofthe rotation of the spindle means B by the air motor D, the spindlemeans B dynamically seals off the high pressure portion HP in the cavity2 and engages the cylinder bushing 1 of the housing means A so that asthe pressure in the high pressure portion HP and on th spindle means Bincreases, the housing means A rotates with the spindle means B thusapplying a torque to the nut N.

In this embodiment the housing means A is made of light but strongmaterial, such as aluminum or an alloy thereof, and the spindle means 13is fabricated of a heavier material, such as tungsten, so that the massof the spindle means B is relatively greater than the mass of the housing means A Further, in order to employ any power source, such as theelectric motor Da (FIG. 14) which power source is operable atapproximately constant velocity, torsion means, such as a torsion springis interposed between a drive shaft 6d of the electric motor Da and themodified rear end cap 4Z1 of the housing means A The drive shaft 6t! isrotatable in a bushing 61 in the rear end cap 4b. As the electric motorEa rotates at constant velocity and as the above descdbcd impulse takesplace, the housing means A decelcrates but the electric motor Docontinues to rotate at approximately constant velocity. As a result thetorsion spring 59- is loaded by the relative rotary movement bet-weenthe housing means A and the electric motor Da. At the start of the nextcycle of operation of the impulse tool T, the new loaded torsion spring5? accelerates the housing means A to enable the latter to catch up withelectric motor Du.

Further as shown in FIGS. 15 and 16, the impulse tool T can be used as asource of impulses for driving an impact tool, such as a hammer H Inthis embodiment the front shaft portion 16 is held stationary bysecuring such front end portion 16 (by screws 62 (FIG. 15 extendingthrough a collar 63 and the front flanged member Hf) to the frontflanged member Hf. As shown in FIG. l6, during the impulse, oil F fromthe high pressure portion HP flows (in the direction of the arrows)through a lateral passageway 64 in the spindle 15 and through aconnecting vertical passageway 65 (FIGS. 15 and 16) in the front shaftportion 16. The high pressure oil F then flows through a coupling means,such as an elbow 66, and into operating means, such as a hydrauliccylinder 67, where the series of impulses produced by the impulse tool Tmove a piston 68 (and the hammer H carried thereby) against the actionof a spring 68a between the solid line and dotted line positions shownin FIG. 15. The piston 63 carries a seal, such as an O-ring 67a. Byimmobilizing the spindle means B (i.e. front shaft portion 16) a sourceof fluid impulses of maximum pressure is generated immediately on thefirst impulse. It will be understood by those skilled in the art thatthe angular disposition of the hydraulic cylinder 67 with respect to thelongitudinal axis of the impulse tool may be varied by the use of elbows66 of the desired angularity.

In the embodiment shown in FIG. 15a the front spindle portion 16 rotatesand the front end cap 3a of the housing means A is aflixed by means ofscrews 62a to the inserts 33 and to the front flanged member H Theimpulses are transmitted through passage means, such as the passages 64and 65, and the coupling 66a to the hydraulic cylinder (not shown) tocause reciprocating movement of the piston (not shown) and the tool (notshown), all of which elements 660, etc., are being rotated by the frontspindle portion 16.

Referring now to FIGS. 15b and 1611 it will be understood that thecylinder bushing 1 of the housing means A has a nipple 65a incommunication with the oil F, depending therefrom through the front endcap 3b and in communication with a coupling means, such as the nipple65b, which nipple 65b leads to a hydraulic cylinder (not shown) butsimilar to the hydraulic cylinder shown in FIG. 15.

In order to translate the reciprocating motion of the piston 63 intorotary motion and thereby rotate a rotary tool, such as a drill orrotary nut setter D such drill or rotary nut setter D (FIG. 17) ismounted in a converter 69 aflixed to the hydraulic cylinder 67 and inoperable engagement with the piston 68.

'It will be recognized by those skilled in the art that the objects ofthe present invention have been achieved by the provision of an impulsetool which applies a force, namely oil pressure, on the spindle bladeand spindle for a short time (namely during the dynamic sealing portionof the operating cycle of the impulse tool) thus providing operation ina fluid at low force levels with resultant minimum wear and attendantlonger service life than conventional impact tools.

The impulse tool of the present invention is operable to control thefinal torque on a threaded fastener accurately and precisely withinpredetermined practical limits. Further, because of the simplicity ofits structure, the impulse tool is easy and economical to manufacture.In addition the impulse tool provides relatively quiet operation ascompared with conventional impact tools. The impulse tool acts as a sealdynamically and as a valve statically; has all of the advantages of thestall type, clutch ty e and impact type tools and none of thedisadvantages thereof; is lighter in weight and faster in operation thanthe tools of the stall type and clutch type. The present invention alsocontemplates the use of the impulse tool as as ource of fluid impulses,which impulses can be utilized to drive a conventional reciprocatingtool, such as a hammer, or a conventional rotary tool, such as a drill.The impulse tool is operable to apply a torque or a series of impulsesat any desired angle with respect \to the longitudinal aXis of theimpulse tool.

While in accordance with the patent statutes one best known embodimentof the present invention has been illustrated and described in detail,it is to be particularly understood that the inveniton is not limitedthereto or thereby.

I claim:

1. An impulse tool for applying a torque to an object, said impulse toolcomprising housing means sealingly containing a fluid, spindle means insaid housing means and in said fluid, drive means operatively associatedwith one of said housing means and said spindle means for causingrelative rotary movement between said housing means and said spindlemeans, the other of said housing means and said spindle means beingadapted to engage said object, sealing means on one of said housingmeans and said spindle means, a first sealing portion on said housingmeans, a second sealing portion on said spindle means, said firstsealing portion and said second sealing portion being disposed insealing relation during a relatively small portion of each revolution ofsaid relative rotary movement, said first sealing portion and saidsecond sealing portion and said sealing means being operable during saidrelative small portion of each revolution of said relative rotarymovement to dynamically seal off a portion of said fluid so that thepressure in said portion of the fluid and on said other increasesthereby causing the other of said housing means and said spindle meansto rotate with respect to said one and to apply a torque to said object.

2. The impulse tool as set forth in claim 1 having relief valve means inone of said housing means and said spindle means in communication withsaid fluid on high and low pressure sides of said fluid during theportion of each revolution of said relative rotary movement when saidfirst sealing portion, said second sealing portion and said sealingmeans dynamically seals off said portion of the fluid and operable torelieve the pressure in said portion of the fluid when said pressurereaches a predetermined 9 value which corresponds to maximum desiredtorque on said object.

3. The impulse tool as set forth in claim 1 having reservoir means inone of said housing means and said spindle means in communication withsaid fluid and operable to supply additional fluid to said housing meansin the event of leakage of fluid therefrom and to limit the staticpressure in said housing means when thermal expansion and contractionoccurs.

4. T he impulse tool as set forth in claim 1 having relievalve means inone of said housing means and said spindle means in communication withsaid fluid on high and low pressure sides of said fluid during theportion of each revolution of said relative rotary movement when saidfirst sealing portion, said second sealing portion and said sealingmeans dynamically seals off said portion of the fluid and operable torelieve the pressure in said portion of the fluid when said pressurereaches a predetermined value which corresponds to maximum desiredtorque on said object, and cut off means disposed in said one inoperative relation to said relief valve means and operable by actuationof said relief valve means to shut ofl? said impulse tool when apredetermined torque on said object is obtained.

5. The impulse tool as set forth in claim 1 wherein said drive meanscomprises an air motor.

6. The impulse tool as set forth in claim 1 wherein said drive meansoperates at approximately constant velocity and having torsion meansconnected in said drive means and said one to permit said drive means tooperate at approximately constant velocity during said relative rotarymovement.

7. The impulse tool as set forth in claim 1 wherein said housing meanscomprises a cylinder bushing provided with an eccentric cavity in whichfluid is disposed, and means for sealing said fluid in said cavity.

8. The impulse tool as set forth in claim 1 wherein said spindle meanscomprises a spindle rotatable in said housing means and provided with aslot, a spindle blade reciprocable in said slot in the spindle, biasingmeans in said spindle for biasing said spindle blade into engagementwith said housing means, and reverse valve means in said spindle forpermitting flow of fluid into said slot behind said spindle blade.

9. An impulse tool for applying a torque to an object, said impulse toolcomprising housing means sealingly containing a fluid, spindle means insaid housing means and in said fluid and adapted to engage said object,drive means connected to said housing means for rotating said housingmeans with respect to said object and said spindle means, sealing meanson one of said housing means and said spindle means, a first sealingportion on said housing means, a second sealing portion on said spindlemeans, said first sealing portion and said second sealing portion beingdisposed in sealing relation during a relatively small portion of eachrevolution of said housing means, said first sealing portion and saidsecond sealing portion and said sealing means being operable during saidrelatively small portion of each revolution of said housing means todynamically seal ofi a portion of said fluid so that the pressure insaid portion or" the fluid and on said spindle means increases therebycausing said spindle means to rotate with respect to said housing meansand to apply a torque to said object.

10. The impulse tool as set forth in claim 9 having relief valve meansin one of said spindle means and said housing means in communicationwith said fluid on high and low pressure sides of said fluid during theportion of each revolution of said housing means when said first sealingportion, said second sealing portion and said sealing means dynamicallyseals off said portion of the fluid and operable to relieve the pressurein said portion of the fluid when said pressure reaches a predeterminedvalue which corresponds to maximum desired torque on said object.

11. The impulse tool as set forth in claim 9 having reservoir means inone of said housing means and said spindle means in communication withsaid fluid and operable to supply additional fluid to said housing meansin the event of leakage of fluid therefrom and to limit the staticpressure in said housing means when thermal expansion and contractionoccurs.

12. The impulse tool as set forth in claim 9 having relief valve meansin one of said housing means and said spindle means in communicationwith said fluid on high and low pressure sides of said fluid during theportion of each revolution of said housing means when said first sealingportion, said second sealing portion and said sealing means dynamicallyseals off said portion of the fluid and operable to relieve the pressurein said portion of the fluid when said pressure reaches a predeterminedvalue which corresponds to maximum desired torque on said object, andout 01f means disposed in said one in operative relation to said reliefvalve means and operable by actuation of said relief valve means to shut01f said impulse tool when a predetermined torque on said object isobtained.

13. The impulse tool as set forth in claim 9 wherein said drive meanscomprises an air motor.

14. The impulse tool as set forth in claim 9 wherein said drive meansoperates at approximately constant velocity and having tension meansdisposed between said drive means and said housing means to permit saiddrive means to operate at approximately constant velocity duringacceleration and deceleration of said housing means.

15. The impulse tool as set forth in claim 9 wherein said housing meanscomprises a cylinder bushing provided with an eccentric cavity in whichsaid fluid is disposed, and means for sealing said fluid in said cavity.

16. The impulse tool as set forth in claim 9 wherein said spindle meanscomprises a spindle rotatable in said housing means and provided with aslot, a spindle blade reciprocable in said slot in the spindle, biasingmeans in said spindle for biasing said spindle blade into engagementwith said housing means, and reverse valve means in said spindle forpermitting flow of fluid into said slot behind said spindle blade.

17. An impulse tool for applying a torque to an object, said impulsetool comprising housing means sealingly containing a fluid and adaptedto engage said object, spindle means rotatable in said housing means andin said fluid, drive means connected to said spindle means for rotatingsaid spindle means with respect to said object and said housing means,sealing means on said spindle means, a first sealing portion on saidhousing means, a second sealing portion on said spindle means, saidfirst sealing portion and said second sealing portion being disposed insealing engagement during a relatively small portion of each revolutionof said spindle means, said first sealing portion and said secondsealing portion and said sealing means being operable during saidrelative small portion of each revolution of said spindle means todynamically seal off a portion of said fluid so that the pressure insaid portion of the fluid and on said housing means increases therebycausing said housing means to rotate with respect to said spindle meansand to apply a torque to said object.

18. The impulse tool as set forth in claim 17 having relief valve meansin one of said housing means and said spindle means in communicationwith said fluid on high and low pressure sides of said fluid during theportion of each revolution of said spindle means when said first sealingportion, said second sealing portion and said sealing means dynamicallyseals oif said portion of the fluid and operable to relieve the pressurein said portion of the fluid when said pressure reaches a predeterminedvalue which corresponds to maximum desired torque on said object.

19. The impulse tool as set forth in claim 17 having reservoir means inone of said housing means and said spindle means in communication withsaid fluid and operable to supply additional fluid to said housing meansin the event of leakage of fluid therefrom and to limit the staticpressure in said housing means when thermal expansion and contractionoccurs.

20. The impulse tool as set forth in claim 17 having relief valve meansin one of said housing means and said spindle means in communicationwith said fluid on high and low pressure sides of said fluid during theportion of each revolution of said spindle means when said first sealingportion, said second sealing portion and said sealing means dynamicallyseals 011' said portion of the fluid and operable to relieve thepressure in said portion of the fluid when said pressure reaches apredetermined value which corresponds to maximum desired torque on saidobject, and cut off means disposed in said one in operative relation tosaid relief valve means and operable by actuation of said relief valvemeans to shut off said impulse tool when a predetermined torque on saidobject is obtained.

21. The impulse tool as set forth in calim 17 wherein said drive meanscomprises an air motor.

22. The impulse tool as set forth in claim 17 wherein said drive meansoperates at approximately constant velocity and having torsion meansdisposed between said drive means and said spindle means to permit saiddrive means to operate at approximately constant velocity duringacceleration and deceleration of said spindle means.

23. The impulse tool as set forth in claim 17 wherein said housing meanscomprises a cylinder bushing provided with an eccentric cavity in whichsaid fluid is disposed, and means for sealing said fluid in said cavity.

24. The impulse tool as set forth in claim 17 wherein said spindle meanscomprises a spindle rotatable in said 12 housing means and provided witha slot, a spindle blade reciprocable in said slot in the spindle,biasing means in said spindle for biasing said spindle blade intoengagement with said housing means, and reverse valve means in saidspindle for permitting flow of fluid into said slot behind said spindleblade.

References Cited in the file of this patent UNXTED STATES P TENTS1,422,929 Cooke July 18, 1922 1,996,341 McClelland Apr. 2, 19352,050,955 Lee Aug. 11, 1936 2,240,662 Montgomery May 6, 1941 2,292,146Meunier Aug. 4, 1942 2,293,786 Worden Aug. 25, 1942 2,304,907 Goodson eta1. Dec. 15, 1942 2,451,118 Pyle Oct. 12, 1948 2,560,716 Bortle et al.July 17, 1951 2,564,212 Ramsey Aug. 14, 1951 2,565,289 Zak Aug. 21, 19512,565,579 Thorner Aug. 28, 1951 2,633,216 Zak Mar. 31, 1953 2,781,682Herndon Feb. 19, 1957 2,796,789 Rice et al. June 25, 1957 2,809,734Graybill Oct. 15, 1957 2,834,442 Sturrock May 13, 1958 2,893,278 RiceJuly 7, 1959 2,947,283 Roggenburk Aug. 2, 1960 2,956,450 Yule Oct. 18,1960 2,986,024 Power May 30, 1961 2,990,812 Gattiker et al. July 4, 19613,024,609 Gauldie Mar. 13, 1962 3,029,605 Gauldie Apr. 17, 1962

1. AN IMPLUSE TOOL FOR APPLYING A TORQUE TO AN OBJECT, SAID IMPLUSE TOOLCOMPRISING HOUSING MEANS SEALINGLY CONTAINING A FLUID, SPINDLE MEANS INSAID HOUSING MEANS AND IN SAID FLUID, DRIVE MEANS OPERATIVELY ASSOCIATEDWITH ONE OF SAID HOUSING MEANS AND SAID SPINDLE MEANS FOR CAUSINGRELATIVE ROTARY MOVEMENT BETWEEN SAID HOUSING MEANS AND SAID SPINDLEMEANS, THE OTHER OF SAID HOUSING MEANS AND SAID SPINDLE MEANS BEINGADAPTED TO ENGAGE SAID OBJECT, SEALING MEANS ON ONE OF SAID HOUSINGMEANS AND SAID SPINDLE MEANS, A FIRST SEALING PORTION ON SAID HOUSINGMEANS, A SECOND SEALING PORTION ON SAID SPINDLE MEANS, SAID FIRSTSEALING PORTION AND SAID SECOND SEALING PORTION BEING DISPOSED INSEALING RELATION DURING A RELATIVELY SMALL PORTION OF EACH REVOLUTION OFSAID RELATIVE ROTARY MOVEMENT, SAID FIRST SEALING PORTION AND SAIDSECOND SEALING PORTION AND SAID SEALING MEANS BEING OPERABLE DURING SAIDRELATIVE SMALL PORTION OF EACH REVOLUTION FO SAID RELA-